Site-specific DNA cleavage by vaccinia virus DNA topoisomerase I: Role of nucleotide sequence and DNA secondary structure Journal Article
| Author: | Shuman, S. |
| Article Title: | Site-specific DNA cleavage by vaccinia virus DNA topoisomerase I: Role of nucleotide sequence and DNA secondary structure |
| Abstract: | Cleavage of linear duplex DNA by purified vaccinia virus DNA topoisomerase I occurs at a conserved sequence element (5′-(C/T)CCTT↓) in the incised DNA strand. Oligonucleotides spanning the high affinity cleavage site CCCTT at nucleotide 2457 in pUC19 DNA are cleaved efficiently in vitro, but only when hybridized to a complementary DNA molecule. As few as 6 nucleotides proximal to the cleavage site and 6 nucleotides downstream of the site are sufficient to support exclusive cleavage at the high affinity site (position +1). Single nucleotide substitutions within the consensus pentamer have deleterious effects on the equilibria of the topoisomerase binding and DNA cleavage reactions. The effects of base mismatch within the pentamer are more dramatic than are the effects of mutations that preserve base complementarity. Competition experiments indicate that topoisomerase binds preferentially to DNA sites containing the wild-type pentamer element. Single-stranded DNA containing the sequence CCCTT in the cleaved stand is a more effective competitor than is single-stranded DNA containing the complementary sequence in the noncleaved strand. |
| Keywords: | nonhuman; structure-activity relationship; dna; molecular sequence data; vaccinia virus; base sequence; dna structure; hydrogen bonding; binding sites; dna mutational analysis; nucleic acid conformation; dna topoisomerase; dna topoisomerases, type i; oligonucleotides; vaccinia; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s. |
| Journal Title: | Journal of Biological Chemistry |
| Volume: | 266 |
| Issue: | 3 |
| ISSN: | 0021-9258 |
| Publisher: | American Society for Biochemistry and Molecular Biology |
| Date Published: | 1991-01-25 |
| Start Page: | 1796 |
| End Page: | 1803 |
| Language: | English |
| PUBMED: | 1846364 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Article -- Export Date: 27 September 2019 -- Source: Scopus |
